Shaking conveyer



April 14, 1936.

H. cREMER SHAKING coNvEYER Filed Jah. 12, 1955 0 f l 0 a f nve niger.'Ha n.5 Cremer A Norneys:

Patented Apr. 14, Y 1936 ,ai y..

y y UNITED STATES SHAKING CONVEYEB Hans `Cremer, Bochum, Germany,assignor to Gebr. EickholMaschinenfab1-ik und Eisengiesserei, Bochum,Germany Application January 12, 1935, serial No. 1,566

ous conditions of service, since the forces to be transmitted by thespring attachment to the conveyer depend vupon the length of theconveyer concerned and upon the quantity of goods to be conveyed by it,that means, upon the masses to be moved by the conveyerin the specialcase.

kwhich frequently vary within comparatively wide limits. Now, anadoption of the spring power to the forces of motion to be vtransmittedto the shaking conveyer cannot be obtained by varying the tension of thespring, since the so-called spring-constant, that is the proportion ofthe power to the. stroke of the spring, cannot be y altered by alteringthe tension. Consequently, the eiect of a determined spring arrangementis in every case only satisfactory within determined limits, that means,within determined conveyer lengths andadetermined quantities ofwthegoods:Hl

to be conveyed, while outside these limits the favorable effect oi thespring attachment d egenerates into a noxious eiect which maylead todisturbances of the conveying work and destruction of the springsthemselves. Such destructive effect arises in particularif the criticalnumber of oscillations, which decreases withincreasing mass, becomessmaller than the number of the driving strokes, that is, if the criticalnumber of oscillations of the oscillating system formed by the springattachment and the conveyer with larger masses of the conveyer and ofIthe goods to be conveyed is reached by the rate of driving strokes. Inorder to render possible such an adoption of the springs to greaterlengths of the conveyer and, in particular, to prevent surpsing of thecritical number of oscillations, one must, for greater conveyer lengthsor for conveying larger masses of goods, either reduce the number ofstrokes of the drive, which would be very troublesome and expensive inthe drive by alternating current employed in the most cases, or springsof a greater constant would have to be used, the exchanging of whichwould be very troublesome during service. f

The object of the invention, therefore, is a' spring attachment forshaking conveyers in which PATENT OFFICE ermany January 20, 1934 (Cl.'Z4- 26) an alteration of the spring constant is possible withoutexchange of the springs. This object is obtained according to theinvention by a spring attachment in vwhich a reciprocating gear part isarranged between, and acts upon two springs of the same direction ofaction. In known spring attachments of this type, the attachment at thesame time serves to convert a sinusoidal gear motion, not suited for themotion of the conveyer, into the required motion, in which the conveyerat the end of its conveying stroke is notably retarded. Thereupon theconveyer suddenly reverses its motion and at the end of its back strokeit comes gently to rest and is forwarded again with at leastapproximately uniform acceleration. To this end two springs of diierentconstant are provided in the known conveyer gears, the spring of greaterconstant serving to effect the retardation at the end of the feedstroke. In order that now in this case the different constants of thetwo springs come into effect, it is necessary that that part of thegear, which engages between the springs at any change of stroke, islifted 'at least from one of the springs, since, if the two springswould be effective in both directions, they would act as one sole springof one permanently uniform spring: constant.

Forthe purpose of disclosing my invention I have illustrated certainembodiments thereof in the accompanying drawing in which- Figures 1, 2and 3 are diagrams of the action produced by the springs; V

Figure 4 is a side, elevation partly in section of one form of theinvention;

Figure 5 is a vertical section of. another modication; and

Figure 6 is a plan view of a twin gear. Figure 1 is a spring diagram andillustrates the mode of operation of this known spring at tachmentcomprising two springs of diierent constant, in which the parttransmitting the driving force to the conveyer temporarily is liftedfrom one of the'two springs. In this diagram c1 denotesthe constant ofthe strong spring which temporarily is released in the stroke in thedirection of feed, and c2 denotesthe constant of the weak spring. Aslong as the two springs are ,under` tension, that means, the one springis compressed more highly while the other spring is releasedcorrespondingly, this spring attachment operates with the springconstant aLl-c2, and'.

spring attachment in which the two springs have equal initial tension.If, now, the gear part en- .gaged and reciprocating between the twosprings moves so as to compress the strong spring, while the we'akspring is released correspondingly, the spring powers increase anddecrease according to the left-hand half `*of the diagram. If, however,the gear part moves in opposite direction from the central position y-y,as illustrated in the right-hand half of the diagram of Figure 1, thestrong spring is further released until it is lifted wholly from thegear part in the line :r--x, so that thereafter only the weak spring iseiective which continues tov be compressed.

As to be seen in the diagram, now in the line :r-:v the eiect of theforces of the spring attachment is unsteady, which results in ashockwise stress of the gear. Furthermore, an alteration of the initialtension of the springs of this arrangement does not give an alterationlof the spring constant of .the attachment, that means, the springattachment is not capable of being adapted to the action ofwidelyfvarying forces of masses.

Here the invention offers a remedy. According to the invention, incontrast to the known spring attachment hereinbefore described, in lieuof two springs of different constant two springs are made use of havingequal or at least approximately equal constants. In order that thisspring attachment is capable of operating selectively with a smaller ora, greater constant, according to the invention springs are used of sucha power, that with a high mitin tension both these springs remain unde`tension in both directions of motion. The spring coils do therefore notrest completely 'on one another, and none of thesprings is lifted fromthe gear part engaged between them. On the other hand, if the springshave no or only a small initial tension, the one spring is released atleast when the other spring begins to be compressed. 'Ihe effect of sucha spring attachment is as follows: Since the springs are initially notcompressed, or only to a small extent, alternately one of the springs isreleased in the reciprocating motion, when the other spring begins to becompressed. This is thevcase when the two springs in thecentral'posltion of the attachment abut against the intermediate gearpart without play and without any or substantial initial tension. Whenthis attachment is moved, as shown in the spring diagram of Figure 2,only one spring of the constant c1 acts in the one direction, while onlythe other spring of constant c2 acts in the other direction, theseconstants c1 and c2 being at least approximately equal to one another.Consequently, the change of force takes place steadily, as Figure 2shows, that is, without causing knocking in the gear.

If, on the other hand, sogreat an initial'tension is given to thesprings, that Athe spring attachment is not lifted from any of the twosprings -in both directions of motion, so that both springs remain undertension in both directions, and if,y

y ment as shown in thisfgu're the two springs abut againstl theintermediate gear partfwith equal initial tension. If the'gear movesfrom this central position in the one or other direction, the tension ofthe one spring increases. as shown in the diagram of Figure 3, and thatof the other` spring decreases correspondingly. The action of the springattachment here i's uniform in the two directions of motion and there isin every direction a spring constant of the amount aLl-c2, that is,provided that springsof equal or approximately equal const/ants `andhaving twice the amount of springs without initial tension are used. Thetransmission of the power is also in this case steady, like in the caseof springs under no initial tension, as to be seen in Figure 3.

The described construction of spring attachment is theiirst to enable anadaption of the action of such attachment with shaking conveyers withincertain limits to the varying length of the conveyer and to the varyingquantity of goods to be fed, both of which factors vary according to theconditions of service. This adaption is effected 'by an alteration ofthe spring constant, Without an exchanging of the springs themselves,and merely by altering their initial tension.

Since in the present case the two springs have at l t approximatelyequal constants, these sp gs* in themselves do not produce the typicalVlaw of shaking motion. On the contrary, the intermediate gear has to bedesigned in these conveyers in such a manner, that the intermediatereciprocating spring plate or piston moves corresponding to the law ofshaking motion.

In other words, a great retardation and acceleration at the end of thefeed stroke and a. gently terminating back stroke, as well as a ratheruniform and not too great acceleration up toward the end of the 4feedstroke of the conveyer is to be obtained. To this end the conveyer gearmay be designed in any known manner.

In order now, that the invention may be clearly.

understood and readily carried into effect, three embodiments of shakingconveyers constructed according to the invention are illustrated in theaccompanying drawing by way of example by the Figures 4, 5 and 6.

In the embodiment shown in Figure 4 the spring attachment comprises acylinder 3 which at 2 is hingedly fixed tolthe shaking conveyer I. Inthe cylinder 3 are disposed two springs 4 and 5 of equal or nearly equalpower. A rod 6 is engaged by means of a collar or piston between thesprings 4, 5, the other end of spring 5 abutting against the end wall 8of the cylinder 3, while spring 4 abuts on its outer end against a cover9 screwed into the cylinder and shiftable in axial direction. Bydisplacing the cover 9 the tension of the springs 4, 5 can be adjusteduniformly in such a manner, that with comparatively short shakingconveyers the collar 'l is alternately lifted from the springs 4 and 5immediately or shortly after its motion from the central position. Withlong conveyers the collar 'l remains in elastic close contact with bothsprings in both directions of movement.' The power of the springs 4 and5 has to be determined in such a manner, that the springs do not becomesolid even with the longest conveyers and the largest quantities ofgoods to be conveyed for which the spring attachment is intended. f-

In theI embodiment shown in Figure 4 the gear serving to reciprocate therod 6 in a manner giving a' satisfactory conveying motion comprises arotary motor I 0, gear wheels Il, I2 actuated by it, a shaft i 4carrying an eccentric or crank, a

rod' l5, and a shaft I1 set inangular motion by means of 'a rock leverI6 mounted thereon.

conveyer gear comprises gear wheels 2| and 22,.

an elliptic spurwheel 23 revolving with the latter and mounted in one ofits foci 24, and a companion elliptic wheel 25 in' mesh with wheel 23and likewise mounted in one of its foci 26. It

actuates a crank 21 which transmits its motion through a rod 28 to acrosshead 29. The latter is hingedly fixed to a cylinder 30 which likein the first-described Aembodiment includes `two springs 3| and 32disposed in alinement and having equal or nearly equal power. Betweenthe springs is arranged a collar or piston 33 which is hingedly fixed tothe conveyer through a rod 34. For the purpose of uniformly adjustingthe springs 3|, 32 there is again provided an axially adjustablecylinder cover 30'. As may be seen in Figure 6, this gear may also beconstructed as twin gear, by two rods 36, 31 with appurtenant crossheads38, 39 being reciprocated according to the law of conveyer motion by thecrank shaft 354 and acting upon two rods 40, 4| of the twin springattachment.

It is to be understood, as a matter ofcourse, that the actuating gearmay also be designed in `any other suitable manner, provided its actionis such as to give a driving motion of the spring attachment favorablefor the conveying effect of the shaking conveyer.

What I claim'and desire to secure by Letters Patent iszl f 1. A drivefor a shaking conveyer having a conveying member comprising a drivingmechanism, said mechanism including a driving member which is movedaccording to the law of conveyer motion, and means connecting saiddriving member to said conveying member, said connecting means includingelements pivotally connected to said driving member and conveying memberrespectively, a pair of aligned springs of equal strength and stroke, amember on one of said elements located between said springs, and meanson the other element engaging the outer ends of the springs, said lastmember alternately compressing said springs in opposite directions, saidsprings remaining elastic when said-compressing. member is incompressing position, whereby the reciprocating and accelerating motionsof the driving and connecting means and of said cony on said otherelement including a member, saidl member being longitudinally adjustablewith respect to said springs for adjusting the tension of said springsuniformly with respect to each other, means for guiding said compressingmember an means for guiding said springs.

4. In a device according to claim 1,'said driving mechanism furtherincluding a motor, and a transmission gearing connected to said motorand said driving member respectively, said gearing comprlsingmeans formoving said member according to the law of conveyer motion, the means onsaid other element including a. casingA secured at one end to said otherelement, said springs being enclosed within said casing and guidedthere-'- by, means threadedly secured to the free end of s'aid casing,said means being longitudinally ad- `instable with respect to saidcasing for adjusting the tension of said springs uniformly with respectto each other, and means on said casing for guiding said compressingmember.

5. A drive for a shaking conveyer having a conveying member comprising adriving mechanism, said mechanism including a driving member which ismoved according to the law of conveyer motion, and means connectingsaiddriving member to said conveying member, said connecting meansincluding elements hingedly connected to said driving member andconveying member respectively, a pair of aligned springs of equalstrength and stroke, a member on one of said elements located betweensaid springs, and means nmhe other element engaging the outer ends o thesprings, said last member alternately compressing vsaid springs inopposite directions, said springs being so dimensioned that operationunder high initial tension both s gs remain elastic and bear againstboth of said elements, while underlow initial tension each spring isrelieved from load at least shortly after the other spring takes up theload, whereby the reciprocating and accelerating motions of the drivingand connecting meansand of-said conveying member are modified and thechange of force from one direction to the other takes place steadily andsmoothly. n

6. A drive for a shaking conveyer having a conveying member comprising adriving mechanism, said mechanism including a motor, transmissiongearing connected to said motor, means connecting said gearing tovsaidconveying member, said connecting means comprising a shaft,

said shaft being hingedly connected to said gearing, a casing hingedlysecured at one end to said conveying member, apair of aligned springs ofequal lengthY and stroke enclosed by said casing, a piston on saidshaft, said-piston being slidably arranged within said casing betweensaid springs and being guided by said casing, a. member threadedlysecured to the free end of said casing, said member being longitudinallyadjustable with respect to said casing for adjusting the tension of saidsprings uniformly with respect to each other, said shaft slidablyengaging said member and being guided thereby, means at the other end ofsaid casing for guiding said shaft, said gearing comprising means formoving the piston accordling to the law of-conveyer motion, said pistonal-- ternately compressing said springs in opposite directions, saidsprings being so dimensioned that in operation under high initialtension b othi springs remain elastic and bear against both of 65 saidelements, while under low initial tension each spring is relieved fromload at least shortly after the other spring takes up the load, wherebythe reciprocating and accelerating motions of the driving and'connectingmeans and of said conveying 'memberare modified and the change of i forcfromv one direction to the other takes place steadily and smoothly.

7. In,a device according to claim 6 means at the other end of saidcasing for guiding said shaft.

8.l A- drive for -a shaking conveyer having a conveying membercomprising a driving mechanism,

' said mechanism including a motortransmission conveying member, apiston on said shaft located' between said springs, said casinglongitudinally slidable with respect to said piston and guiding thesame, a member threadedly secured to the free end of said casing andbeing longitudinally adjustable with respect to said casing for adjust-Ving the tension of said springs uniformly with respect to each other,said member slidably engaging said shaft and guiding the same, saidgearing comprising means for moving said casing according to the law ofconveyer motion, the end walls of said casing alternately compressingsaid springs in opposite directions, said springs being so dimensionedthat in operation under high initial tenson both springs remain elasticand bear against both of said elements, while under low initial tensioneach spring is relieved from 10 load at-least shortly after the otherspringtakes up the load, whereby the reciprocating and acceleratingmotions of the driving and connecting means and of said conveying memberare modiiied and the change of force from one direction- 15 to theother. takes piace steadily and smoothly.

HANS CREMER.

